function toggleSound() {
    var video = document.getElementById("bgVideo");
    if (video.muted) {
        video.muted = false;
        document.getElementById("videoToggle").innerHTML = '<i class="material-icons">volume_up</i>';
    } else {
        video.muted = true;
        document.getElementById("videoToggle").innerHTML = '<i class="material-icons">volume_off</i>';
    }
}